In the manufacture of card and board cartons and boxes from blanks or a web of material, the necessary cutting and creasing is effected by so called printer's rule which has a sharpened or rounded edge, according to purpose, and is mounted edge-on to a base plate or forme. The box maker is continually making new formes to suit new box sizes or arrangements, and because each is different from the last, and usually only one is required, these are handmade by bending the selected rule to the required configuration before mounting on the forme. The rule is made to different dimensions and an appropriate one is selected according to the nature of the material to be used for the boxes.
The conventional method of bending the rule involves selecting an appropriate pair of forming tools of which one is a post like member upstanding from a base plate and the second of which has a jaw mounted for reciprocation on the base plate by a lever and crank mechanism. The rule is positioned on the post and the jaw is forced against the post with the rule interposed and this may the bend the rule for example to an angle of 30% about a radius dictated by the diameter of the post. If for example a slot is required in the box, so that two parallel cutting rule portions are to be connected by a small radius, then a post of that radius is mounted in position, and after a first forming operation bringing about a 30% bend, the part-formed rule is displaced about the post and the jaw reciprocation repeated, on a number of occasions, until the required parallel portions are so formed. These operations are relatively slow, and involve substantial physical effort, and involve much time spent interchanging components of the apparatus. The objects of the invention are to provide improvements.